Multiaxial Strength and Deformations of Concrete, Failure Modes and a New Failure Criterion

Abstract

The multiaxial strength of concrete, the associated stress-strain relationships, the failure modes and the failure criteria are again and again in the interest of researchers. After a historical review the most important bi- and triaxial experiments loading through brushes are analyzed. Based on the principal strengths and the loading path-concept a new, transparent type of presentation of the ultimate strength surface (USS) is introduced. For concrete classes ≤ C100 simplified relative strength-increase values are proposed. The difficulties of deformation measurements are reviewed. The outlines of future bi- and triaxial tests are discussed. Two failure modes are appointed. Stress failure criterion of biaxial state of stress are presented. Instead of the Modified Mohr-Coulomb failure criterion Extended Rankine-type failure criteria are proposed. Further systematic tests are necessary to detect the rate of participation of the loading equipment.